<template>
  <!-- 商品分类导航 -->
  <div class="type-nav">
    <div class="container">
      <div @mouseleave="currentIndex = -1">
        <h2 class="all">全部商品分类</h2>
        <div class="sort">
          <div class="all-sort-list2" @click="toSearch">
            <div
              class="item"
              :class="{ item_on: currentIndex === index }"
              @mouseenter="moveInItem(index)"
              v-for="(c1, index) in categoryList"
              :key="c1.categoryId"
            >
              <h3>
                <!-- 第一种将a标签改为router-link -->
                <!-- <router-link
                    :to="{name:'search',
                    query:{categoryName:c1.categoryName, 
                    category1Id:c1.categoryId}
                    }"
                    >{{c1.categoryName}}</router-link> -->

                <!-- 第二种:编程式导航 -->
                <!-- <a 
                    href="javascript:;"
                    @click="
                    $router.push({
                        name:'search',
                        query:{
                            categoryName:c1.categoryName,
                            category1Id:c1.categoryId
                        }
                    }) 
                "
                    >{{c1.categoryName}}</a> -->

                    <!-- 第三种 事件委派 -->
                    <!-- 添加自定义属性 -->
                    <a 
                    href="javascript:;'"
                    :data-categoryName="c1.categoryName"
                    :data-category1Id="c1.categoryId"
                    >{{c1.categoryName}}</a
                    >
                <!-- <a href="">{{c1.categoryName}}</a> -->
              </h3>
              <div class="item-list clearfix">
                <div class="subitem">
                  <dl
                    class="fore"
                    v-for="c2 in c1.categoryChild"
                    :key="c2.categoryId"
                  >
                    <dt>
                      <!-- <router-link
                            :to="{name:'search',
                            query:{categoryName:c2.categoryName, 
                            category2Id:c2.categoryId}
                        }"
                        >{{c2.categoryName}}</router-link> -->

                      <!-- 第二种:编程式导航 -->
                      <!-- <a 
                        href="javascript:;"
                        @click="
                            $router.push({
                                name:'search',
                                query:{
                                    categoryName:c2.categoryName,
                                    category2Id:c2.categoryId
                                }
                            }) 
                        "
                        >{{c2.categoryName}}</a> -->

                        <a href="javascript:;'"
                        :data-categoryName="c2.categoryName"
                        :data-category2Id="c2.categoryId"
                        >{{c2.categoryName}}</a>
                      <!-- <a href="">{{c2.categoryName}}}</a> -->
                    </dt>
                    <dd>
                      <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                        <!-- <router-link
                            :to="{name:'search',
                            query:{categoryName:c3.categoryName, 
                            category3Id:c3.categoryId}
                        }"
                        >{{c3.categoryName}}</router-link> -->


                        <!-- 第二种:编程式导航 -->
                        <!-- <a 
                            href="javascript:;"
                            @click="
                                $router.push({
                                    name:'search',
                                    query:{
                                        categoryName:c3.categoryName,
                                        category3Id:c3.categoryId
                                    }
                                }) 
                            "
                            >{{c3.categoryName}}</a> -->

                    
                        <a 
                        href="javascript:;'"
                        :data-categoryName="c3.categoryName"
                        :data-category3Id="c3.categoryId"
                        >{{c3.categoryName}}</a
                        >
                        <!-- <a href="">{{c3.categoryName}}</a> -->
                      </em>
                    </dd>
                  </dl>
                </div>
              </div>
            </div>
          </div>
        </div>
      </div>
      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import { mapState } from "vuex";
import throttle from "lodash/throttle"; //这样引入体积小
export default {
  name: "TypeNav",
  data() {
    return {
      currentIndex: -1,
    };
  },
  mounted() {
    // 这里的getCategoryList是自己定义的,不是vuex里的
    this.getCategoryList();
  },
  methods: {
    getCategoryList() {
      // 拧开关 触发分发 action对应的函数,本质是在调用action对象的函数
      this.$store.dispatch("getCategoryList");
    },
    //   moveInItem(index){
    //       console.log(index)
    //       this.currentIndex = index
    //   },

    moveInItem: throttle(
      function (index) {
        // 第一个参数要节流的函数
        console.log(index);
        this.currentIndex = index;
      },
      20, // 平均多长时间执行一次
      { trailing: false }
    ),
    toSearch(event){
        // 把元素身上的data-开头的属性和属性值全部都会收集到这个对象
        let dataset = event.target.dataset;
        console.log(dataset)
        // dataset中结构赋值所需要的东西, 但是不一定能拿到
        // 如果点击的是a标签就可以按到两个, categoryname和某个categoryid
        // 如果点击的不是a标签,那么久拿不到任何值,4个undefined
        let {categoryname, category1id,category2id,category3id} = dataset 
    
        if(categoryname){
            // 代表点的是a标签
            let location = {
                name:'search',
            }
            // 携带的query参数
            let query = {
                categoryName : categoryname
            }

            // 判断拿到的到底是哪个a标签
            if(category1id){
                query.category1Id = category1id
            }else if(category2id){
                query.category2Id = category2id
            }else {
                query.category3Id = category3id
            }

            location.query = query

            if(this.$router.params){
                location.params = this.$router.params
            }
            this.$router.push(location)
        }
    }
  },
  // 从vuex里面捞数据,用的computed  (states getters)
  // 从vuex里面捞方法, 用的是methods (actions mutations)
  computed: {
    // 写数组的时候必须满足两个条件
    // 1. 不能使用模块化
    // 2. 名字必须和vuex对应的名字相同
    ...mapState({
      categoryList: (state) => state.home.categoryList, //state是调用的时候vuex自动传的,mapState也是vuex调用的
    }),
  },
};
/*
    beforecreate
    created
    beforemount
    mounted
    beforeupdate

*/
</script>

<style lang="less" scoped>
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &.item_on {
            background-color: peachpuff;
            .item-list {
              display: block;
            }
          }
        }
      }
    }
  }
}
</style>
